Download A4.2.1.MuscleRules

Muscle Rules
Introduction
All movement in the human body, from wiggling a toe or swimming a mile to eating
and digesting a sandwich, is the result of muscle action. In previous lessons, you
have learned about connective and nervous tissue. In this unit, you will explore the
structure and function of another incredible tissue -- the muscle.
When we think of muscles, we usually focus on the muscles that move our bones
and allow us to move about the Earth; the tissues we see from the outside. But
inside the amazing human, you will find other types of muscle tissue that work
silently to move substances around the body. Your heart keeps beating and your
food continues to digest even when you fall fast asleep and close your conscious
mind for the day. Without muscle moving blood or distributing nutrients from food,
the human machine would power down.
There are 206 bones in the human body, but over 600 skeletal muscles allow our
bodies to move in different directions. Over sixty of these muscles are found in your
face alone. You use forty of these muscles every time you frown, but only twenty
muscles when you smile. The human body is even built to make it easier to be
happy than to be sad.
Skeletal muscles are attached to bones with tough cords or sheets called tendons
and these bones meet other bones at junctions called joints. The contraction or
shortening of muscles pulls on bone and moves the body.
In this activity, you will observe and compare the structure and function of the three
types of muscle tissue. You will explore the structure of skeletal muscle both by
looking at slides and by creating a model of a muscle unit. Before you move on to
building actual muscle groups, a series of demonstrations will help you see that the
placement of muscles on bones follows specific patterns and rules. These rules will
later help you construct specific muscle groups on your Maniken®.
Equipment
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Computer with Internet access
Prepared slides of muscle tissue – Carolina Biological Supply Muscle Types Set
Microscope
Laboratory journal
Colored pencils
Spaghetti
Plastic wrap
Pencil
Reference textbook (optional)
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Procedure
Part I- Types of Muscle Tissue
1. Work with your partner to research the three types of muscle tissue: skeletal
muscle, smooth muscle and cardiac muscle.
2. In your laboratory journal, describe what it means if a muscle is striated and what
it means if a muscle is said to be under voluntary control.
3. Create a comparison table (shown below) in your laboratory journal. Each box
should be approximately 2” x 2”. Use information from your research to fill in the
chart. Leave the histology box blank until you begin your microscope work.
Type of
muscle
Striations?
(Y/N)
Voluntary?
(Y/N)
Location in
Body
Function in
Body
Histology
Skeletal
Muscle
Smooth
Muscle
Cardiac
Muscle
4. Use a microscope to view a prepared slide of each type of muscle tissue under
both high and low power.
5. Using colored pencils, draw what you see under high power in the histology
column of your table. Use a reliable website to help you label what you see.
6. Answer conclusion questions 1-2.
Part II: Building Muscle
Joints work together with skeletal muscle to move the human body. In the remainder
of this activity, you will focus on the structure of skeletal muscles, build these
muscles on your Maniken®, and visualize the amazing ability of skeletal muscle to
contact and shorten. But before we look at function, let’s explore structure.
7. In your laboratory journal, draw a diagram of muscle. The following components
should be labeled and identified.
o
o
o
o
o
o
Endomysium
Epimysium
Perimysium
Fascicle
Tendon
Muscle cell/fiber (myofibril)
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8. Using materials of your choosing, construction a model of a muscle make sure all
the components labeled in your diagram in #7 are represented by a specific
material. Make a key for your model.
9. Answer conclusion questions 3-4.
Part III: Muscle Rules
Now that you have learned about muscle structure, let’s start to think about function.
We know what muscles help our skeletal system move, but how are these tissues
oriented on our bodies? What are the rules that muscle live by?
10. Write each muscle rule in your laboratory journal. Add notes or examples to help
you remember the concept.
11. Note that the name of a muscle gives you clues about the makeup of that
muscle. Each muscle is given a Latin name based on one or more of its features.
Take a look at the following muscle names and brainstorm what you can tell
about these muscles simply by their names. Analyze specific words in the name,
roots in the name and relationships to bones you have already studied.
Brainstorm ideas in your laboratory journal. Each pair of muscles represents a
different way in which muscles can be named.
o Trapezius and Rhomboid minor
o Gluteus maximus and Gluteus minimus
o Frontalis and Temporalis
o Orbicularis Oculi and Transverse abdominis
o Flexor Carpi Ulnaris and Extensor digitorum longus
o SternoCleidomastoid and Brachioradialis
o Biceps Brachii and Triceps Brachii
12. Describe the muscle feature that is being used in each naming scenario. For
example, you have probably figured out that trapezius and rhomboids are named
for their shapes. The trapezius muscle is shaped like a trapezoid and the
rhomboids are shaped like rhombuses. See if you can find a pattern in the
remaining pairs.
13. Discuss your findings with the class. Work together to create a list of muscle
features used in naming. Report your findings in your laboratory journal.
14. Answer the remaining conclusion questions.
Conclusion
1. Describe the differences you see in the three types of muscle tissues.
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2. What does it mean when we say a muscle contracts involuntarily? Describe one
body function that is linked to an involuntary muscle contraction.
3. Describe how the structural makeup of a muscle contributes to the muscle’s
ability to do its job.
4. Using your knowledge of tissues, what type of tissue do you think makes up the
three layers of membrane you encountered in your muscle?
5. Explain how you know which attachment of a muscle is the origin and which
attachment is the insertion.
6. Your mom comes back from the doctor and says she has pulled her tibialis
anterior. She knows you are taking Anatomy and Physiology and asks you to tell
her about her injury. Based on the classroom discussion, what can you deduce
about this muscle?
7. When you are cold, your muscles begin to contract involuntarily and cause you to
shiver. Why do you think this occurs? How does the contraction of muscles help
the body maintain homeostasis?
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